Agranulocytosis – what are the causes?

Synonyms in a broader sense


What is agranulocytosis?

With the so-called agranulocytosis, there is an almost complete lack of granulocytes. The granulocytes belong to the white blood cells (leukocytes) and are responsible for defence against infection. With a beginning infection or damage to the bone marrow, the number of granulocytes can be reduced.

This is then referred to as granulocytopenia in medical terminology. As a result, the body’s defence system is now lowered and the susceptibility to infection increased. Agranulocytosis is the extreme form of this condition.

These are the causes of agranulocytosis

Agranulocytosis can be divided into three different forms. In general, a distinction is made between congenital, very rare agranulocytoses and the more frequent acquired type I and type II agranulocytoses. Congenital agranulocytosis is also known as Kostmann syndrome and is a disease in which there are already at birth too few or no granulocytes (more precisely neutrophil granulocytes, a subclass of white blood cells).

The cause lies in a gene mutation, which ultimately leads to maturation disorders of the white blood cells, i.e. not enough mature granulocytes are produced. In the type I reaction, the body’s own immune processes are directed against the granulocytes and destroy them. In contrast, the granulocyte deficiency in type II is based on a lack of formation, often triggered by substances that damage the bone marrow.

Type I can therefore occur more suddenly (acutely) than type II, which worsens over time. There are many different possibilities why a strong reduction of granulocytes can occur. Agranulocytosis can occur if there is an intolerance to some medications such as certain painkillers (analgesics) such as Novalgin® (metamizole), antipyretics (antipyretics), medications that inhibit thyroid function (thyrostatics such as thiamazole and carbimazole), so-called neuroleptics for the treatment of mental illness or certain antibiotics (sulfonamides, cephalosporins, metronidazole). In addition, the application of a cell-killing therapy with so-called cytostatic drugs, e.g. in the form of chemotherapy, can cause the granulocytes to sink. Furthermore, blood formation disorders in the bone marrow are the cause of agranulocytosis.


In addition to the medical history of the disease and recent medication, the examination of the lymph nodes and mucous membranes is of great diagnostic importance. The most important means of diagnosing agranulocytosis is laboratory blood testing. Here the so-called large blood count plays a decisive role.

Here the frequency of the various white blood cell subclasses, which also include granulocytes, is measured separately. The reduction in granulocytes (less than 500 cells/microlitre of blood) can now indicate agranulocytosis. In addition, the determination of other blood values to exclude other diseases (differential diagnosis) is very important. Furthermore, there is the possibility of a so-called bone marrow puncture, in which a small bone marrow sample is taken from the bone crest and examined for a blood cell formation disorder. This examination is carried out under a microscope with the aid of different staining of the sample, through which, among other things, various (surface) characteristics of the cells are made visible, and is usually performed by a pathologist.